Distinct features of matrix-assisted 6μm infrared laser desorption/ionization mass spectrometry in biomolecular snalysis

Distinct features of matrix-assisted 6μm infrared laser desorption/ionization mass spectrometry in biomolecular snalysis
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基质辅助6μm红外激光解吸/电离质谱在生物分子分析中的显着特征

DOI：
10.1021/ac900695q
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发表时间：
2009
期刊：
Anal. Chem.
影响因子：
7.4
通讯作者：
T. Takeuchi and Y. Wada
T. Takeuchi and Y. Wada
中科院分区：
化学1区
文献类型：
--
作者：
M. Tajiri;T. Takeuchi and Y. Wada

文献摘要

相似文献

中红外基质辅助激光解吸/电离质谱（mid-IR-MALDI MS）在6μm波长范围内发射激光，利用CO双键拉伸区域的能量吸收，应用于生物分子分析。 IR-MALDI MS 的柔软性在负离子模式下非常明显，可针对具有硫酸盐、磷酸盐或羧酸盐基团的酸性生物分子产生干净的 [M − H]−离子质谱，从而比紫外 (UV)-MALDI MS 具有更好的灵敏度。由于唾液酸化糖缀合物（例如神经节苷脂）在 IR-MALDI 中发生迅速断裂，因此唾液酸没有大量损失。此外，红外的低光子能量的优点是，首次可以通过MALDI MS检测完整的S-亚硝基化肽的质子化分子。在对包括亚甲蓝和核黄素在内的氧化还原敏感分子的分析中，还原氢化作用很小，这表明与 UV-MALDI 相比，羽流中几乎没有形成氢自由基。与需要较小激光能量密度的有效新基质草酰胺相结合，6 μm IR 波长范围的独特特征预计将消除 MALDI MS 在生物分子分析中的局限性之一。
Midinfrared-matrix-assisted laser desorption/ionization mass spectrometry (mid-IR-MALDI MS) with a laser emission in the 6 μm wavelength range, which utilizes energy absorption at the CO double-bond stretch region, was applied to biomolecular analysis. The softness of IR-MALDI MS was evident in the negative ion mode yielding clean mass spectra of [M − H]−ions for acidic biomolecules with sulfate, phosphate, or carboxylate groups, resulting in better sensitivity than ultraviolet (UV)-MALDI MS. There was no substantial loss of sialic acid due to the prompt fragmentation occurring in IR-MALDI of sialylated glycoconjugates such as gangliosides. Furthermore, the advantage of the low photon energy of IR is that, for the first time, intact protonated molecules ofS-nitrosylated peptides can be detected by MALDI MS. In the analysis of redox-sensitive molecules including methylene blue and riboflavin, reductive hydrogenation was minimal, suggesting few hydrogen radicals to have formed in the plume, in contrast to UV-MALDI. In conjunction with a potent new matrix, oxamide, requiring smaller laser fluence, distinct features of the 6 μm IR wavelength range are anticipated to remove one of the limitations of MALDI MS for biomolecular analysis.